This invention relates generally to tilt-out windows, both of the take-out and non-take-out type. It is particularly directed to those types which include metal (aluminum) or vinyl sash guides or jamb channels, most particularly the vinyl type.
Rigid plastic extrusions are being used more frequently as side jamb channels in windows of this type. Vinyl is typically used and is preferred for this invention. Various types are well known.
Generally, windows of this type have been in use for some time. They are typically provided in a pivoted or tilt-out double-hung version. Their convenience for washing the outside of the window or for replacing broken panes has made them very popular.
The counterbalance system for holding such window sashes in an open or closed position has progressed from a counterweight to a spring balance assembly, various types of which are well known. The spring balance assembly is enclosed in the side jamb channels or weather strips on each side of the window sash.
One of the problems with the pivoted or tilt-out windows has been the retention of the end of the counterbalance spring assembly which is attached to or removably secured to the window sash itself. Since the window sash can be tilted out of the frame, or is even completely removable in some designs, it is desirable that the sash not be vertically movable when tilted out or when its full weight is not available to offset the pull of the spring balance assembly. It is desirable when tilting the window or removing it that the spring balance assembly be retained in a fixed position within the jamb channel by a positive locking arrangement and that the spring assembly not be allowed to move or to snap upwardly in an uncontrolled manner as, after a few such releases, the assembly may be deformed and its effectiveness reduced.
Many types of locking mechanisms have heretofore been available. Reference may be had to U.S. Pat. Nos. 4,364,199; 3,797,168; 3,844,066; 4,079,549; 3,676,956; 3,055,062; 3,842,540; 3,524,282; 3,195,174; and advertising articles entitled Caldwell Aluma-Tilt Balance by Caldwell Manufacturing Co., P.O. Box 444, Rochester, N.Y. 14602 and Jim Walter Window Components, Series 9000 Balance/Weatherstrip for Full-Tilt Windows by J.W.W.C. 1009 Algonquin/Sioux Falls, S.D. 57104.
A still further type of locking mechanism comprises a hook which has a sharp point to embed into one of the walls of the side jamb channel. However, this type of locking engagement is subject to being dislodged when downward pressure is applied.